Cat fight? Need help with a cat injury asap

I've been out of town all weekend. My husband was home with the animals. Each day when I'd ask about the animals he'd report everyone was okay. When I came in last night Sophie my female cat wasn't around. She came back about 8 p.m. favoring her hind rear back leg/hind end and her tail was puffed up- but down (she has a bob tail and her tail is usually up). She doesn't appear to have any wounds or scrapes. Her hind foot looks swollen this a.m. She's upstairs now hiding in the closet. She is purring but won't come down stairs or will she eat anything. My vet isn't open today. Should I seek out an emergency vet? My last emergency vet visit was a very bad experience.

With my dogs I can tell if they need to see a vet asap. With the cat, I just can't tell. Thanks for your time- Kristi